Chapter 5 | The Truth with My Stepsister

“—Dad, can we talk for a sec?”

On the night after spending the day walking around the shopping mall with Yuuri, Mahito visited his father’s study. It was a holiday, so his father was home earlier than usual.

“What’s up, Mahito?”

Noticing Mahito’s serious demeanor, his father adjusted his glasses slightly and tilted his head.

Mahito closed the door behind him. He needed a small, deep breath before speaking his next words.

“I want to know about the parent that Yuuri and I don’t have…”

—Dad and Mom were actually remarried—

When Mahito and Yuuri were told they weren’t blood-related siblings, their father had said that. But because Yuuri had run out afterward, they hadn’t been able to hear any of the details.

Was it a divorce or a death? What had happened to the parent who was no longer here? Whatever the circumstances, it was unlikely to be a pleasant story. Hearing it would probably bring painful feelings.

Mahito understood that much.

—But, including the fact that I couldn’t make up with Yuuri, I want to know everything properly.

It felt like he needed to start by clarifying things here.

His father nodded, as if praising him.

“You’re right. I should’ve been the one to bring it up.”

“No, I know things weren’t exactly in a state to talk about it…”

After that, Yuuri’s memory loss had made it impossible to broach the subject. There hadn’t been a chance to discuss it.

With a small nod, his father pulled a small wooden board from a desk drawer. Upon closer inspection, it was a photo stand. The back had a stand for propping it up, and it was framed. It looked old but had no scratches or stains. It must be something cherished.

Flipping it over, his father handed him the photo.

It showed four young adults, one of them holding a small bundle that looked like a baby.

“This is…?”

His father smiled, a mix of nostalgia and sadness.

“This is the last photo we took together. The baby is you, Mahito, and Yuuri was still in Mom’s belly.”

Now that he mentioned it, two of the people in the photo looked like younger versions of his parents. But his mother had black hair, and his father lacked the wrinkle between his brows, his expression much brighter. They looked so different from now that Mahito hadn’t recognized them at first glance.

The woman holding the baby was someone Mahito didn’t know.

His father pointed to her first.

“This is Haruka-san. Your real mother.”

“…This is her.”

Being told she was his real mother didn’t bring any immediate sense of connection. Still, he thought she looked calm and beautiful.

“What was she like?”

At the question, his father’s face grew lonely.

“She had a wonderful smile. She was the type to drag you along with her energy, and since I was clumsy and bad with people, she always helped me out. She was like a bundle of action.”

His voice carried such affection that it was clear he still loved her.

She seemed to have been a lively person, contrary to the photo’s impression.

Then, his father pointed to the man standing next to his mother, a tall, striking platinum-blond Caucasian man.

“This is Seart. He was an exchange student at my university. We got along great and often went on motorcycle trips together. He’s Yuuri’s real father.”

Seart had his arm around Mahito’s mother, his gaze showing how much he cherished her.

—Yuuri’s silver hair was inherited from him.

His eye color was similar to Yuuri’s too.

The reason it had been kept a secret likely tied to the circumstances of the remarriage, as evidenced by the photo being tucked away.

Despite Mahito’s tension, his father spoke as if recounting an old friend.

“This guy loved his liquor, but he’d get drunk fast, so I often had to pick him up when he passed out. He was an idiot, but a straight-up guy who hated anything crooked. His drinking habits were awful, though.”

Mentioning it twice suggested Seart had been quite a handful in that regard. But his father’s tone carried more fondness than frustration. They must have been good friends.

So why weren’t those two here now?

Leaning back in his chair, his father began to speak in a heavy tone.

“We stayed close even after getting married. Your mom and Haruka-san were best friends, close enough to call each other that. Yuuri’s name even took a character from Haruka-san.”

Mahito knew that Yuuri’s “Yuu” character could be read as “Haruka.”

“That day, the five of us went for a drive. Your mom was close to giving birth, so we thought a change of scenery would help. We took Seart’s car.”

His father let out a deep sigh, heavy with memory.

“A car from the opposite lane, driven carelessly, crashed into us. Seart, who was driving, and Haruka-san, sitting on the right side…”

His voice faltered, and he wiped his eyes, unable to continue.

Mahito had never seen his father so vulnerable. Shaken but needing to confirm, he murmured, “…They passed away?”

“Yeah.”

With Mahito as a baby and Yuuri still in the womb, it must have been right after their marriages. The despair of losing a partner at such a time was beyond Mahito’s imagination.

—I see. That’s why Mom was so shaken when Yuuri got into that accident.

Though the situations differed, losing both her beloved and her best friend in a car accident was traumatic enough. Her daughter being hit would’ve easily dredged up those memories.

His father forced a smile to mask his grief. “After that, your mom needed support with the birth coming up. So I decided to take care of things for Seart’s sake… No, let’s skip that part.”

“Wait, that’s super intriguing…” Mahito pressed, curiosity piqued.

His father looked away, troubled. “…Cut me some slack. Even I get embarrassed.”

Discovering his father’s unexpectedly shy side, Mahito couldn’t push further.

—Come to think of it, I’ve never seen Dad and Mom being all lovey-dovey.

He’d never felt their relationship was bad; in fact, it was clear they cared for each other. But he couldn’t recall them acting particularly couple-like or overly affectionate in front of him and Yuuri. …Not that he’d want to see that, anyway.

He’d assumed that was just how Japanese couples were, but now he worried his father might still be awkward about it. Still, it was clear his father loved both of his wives. And to Mahito, both women were his mothers.

His father continued, voice steady, “It took us both a long time to process our feelings. We didn’t officially register our marriage until much later.”

“Really?”

“I think it was around when you started elementary school. The issue of you and Yuuri having different surnames came up, and that’s when we finally did it.”

“Wait, was that why we moved back then…?”

“Exactly. It was tough on you kids, I know, but it was our way of showing we were committed to doing this together.”

That was when Mahito was six. He barely remembered the place they lived before that. Digging through those memories, he tilted his head.

“Huh? But we’ve always called you guys Dad and Mom… right?”

They’d been living together as a family, after all.

His father scratched the back of his neck, looking reluctant. “…Well, going back and forth between houses was inefficient. Sharing baby supplies made it logical to live in one place.”

It sounded reasonable, but it seemed they’d just been cohabitating without fully committing. Mahito found it a bit pathetic.

—So that’s why it was hard to talk about.

Well, it was probably best not to dig further into his parents’ love story.

Mahito moved to his next question. “So, how did you and… my other mom, Haruka-san, meet? Why did you get married?”

His father made a thoughtful face. “How, huh? Hard to say exactly. Haruka-san and I… we were childhood friends, sort of. A year apart, though.”

“Oh, wow.”

Mahito recalled running into Azumagi and Himemiya at the mall earlier. They had a weird vibe—kind of together, kind of not. Would they end up like that someday?

As Mahito nodded in understanding, his father continued, “We grew up like siblings. I always saw Haruka-san as a little sister.”

That felt similar to Azumagi and Himemiya, and Mahito found it endearing, even if it was about his own parents.

But his calm faded with his father’s next words. “It was around high school, I think. One day, I realized Haruka-san wasn’t just a sister—she was a woman.”

“H-Huh…” Mahito’s voice trembled for some reason.

His father narrowed his eyes nostalgically. “After that, it was like rolling downhill. She was already so clingy, acting like a little sister, dragging me around without caring about my plans. When a girl treats you like that, it’s impossible not to fall for her. So, we got married before I graduated college.”

“Th-That’s how it was…”

Mahito clutched his chest.

—Why am I getting so anxious…?

Somehow, it didn’t feel like someone else’s story—it felt like a glimpse of his own future. Sensing he shouldn’t continue this topic, Mahito changed gears.

“W-Well, what about Mom and… Seart-san? Were they at the same university too?”

His father nodded. “Yeah. Your mom and I were senpai and kouhai from high school. When I started hanging out with Seart, your mom joined us. She’d follow me around calling me ‘Senpai’ back then. She was adorable even then… uh, never mind that part.”

Caught between wanting to hear more and not, Mahito felt increasingly cornered.

“Your mom’s always been so nurturing. Seart was kind of childish, so she couldn’t leave him alone. They were a really great couple.”

Mahito could tell Seart—Yuuri’s real father—was irreplaceable to his father too.

—Mom probably feels the same.

It wasn’t like she was hung up on him, but her silver hair felt more like an homage to Seart than just matching Yuuri’s. Still, Mahito knew both his father and mother loved him and Yuuri equally.

But then, he thought,

—If that accident hadn’t happened, if Dad and Mom hadn’t lost their partners…

What kind of relationship would he and Yuuri have had? “What if” questions might be pointless, but for Mahito right now, it mattered. After all, his relationship with Yuuri had been reset—reset, with the reality of being non-blood-related siblings thrust upon them, leaving everything feeling unresolved.

He wanted answers on how to face his stepsister.

His father smiled at the troubled Mahito. “Was this the kind of talk you wanted?”

“Y-Yeah. I just wanted to know properly.”

It wasn’t a conversation that neatly sorted his feelings, but it felt like a starting point.

Seeing something in Mahito, his father gently placed a hand on his head. “I won’t ask what’s troubling you. But I think the most important thing is ‘what you want.'”

“What I want…?”

Caught off guard, Mahito’s eyes widened as his father continued.

“You look like Haruka-san, but your personality’s like mine. You tend to put yourself last.”

“Is that so…?”

Well, his father definitely had that trait, Mahito thought.

As if expecting that reaction, his father laughed. “Your mom and Haruka-san chewed me out about it plenty, so I’m somewhat aware.”

His father said, “So don’t think about what you should do—think about what you want to do.”

“…Got it.”

That hit the nail on the head. It felt like a punch to the gut.

—What kind of relationship do I want with Yuuri…?

Probably, he wanted to be close. He was tired of her avoiding him like before.

—But what does “close” even mean…?

When he tried to picture it, all he could recall was Yuuri as an elementary schooler. She’d started pulling away noticeably about a year ago, but now that he thought about it, the distance began when she entered middle school. Expecting a high schooler to act like she did as a kid was unreasonable. Yet, realizing he only had such a vague image of “being close” with his stepsister left him stunned.

—But not knowing means I need to start thinking about it from there, right?

Feeling like he’d found something to face, Mahito nodded.

“Dad, thanks for talking to me.”

“Yeah.”

After thanking him, Mahito left his father’s room. As he stepped into the hallway, he saw a figure in front of his stepsister’s room.

“Yuuri…?”

For some reason, Yuuri was standing frozen in front of her room.

“W-What’s wrong?”

Rushing to her side at the unusual sight, Yuuri looked up at him with pitch-black eyes.

“…Onii-san.”

Her voice was trembling. The cheerful demeanor from the mall seemed like a lie—she looked utterly grief-stricken.

“What happened?”

When he grabbed her shoulders, Yuuri leaned into his chest.

“What do I do…? I…”

She mumbled in a faint, fading voice.

◇

[So, your first date with Onii-san went well, huh?]

“A date…? It’s not like that!”

The timeline shifts slightly backward.

Yuuri couldn’t help but raise her voice at the LIME message. After eating pancakes at the mall, her stepbrother had spent the whole day with her, even helping pick out clothes. While chatting with Yamanashi about it, she’d gotten that kind of comment.

—Ugh, Tsukki always jumps to those conclusions…

It wasn’t entirely Tsukki’s fault, though—she’d called it a date to her stepbrother and made things awkward herself. Still, since it wasn’t directly related, she couldn’t exactly complain.

—Besides, thinking about what happened after makes it hard to talk about extra stuff.

Seeing her stepbrother alone with that woman—Himemiya-san, was it?—had felt like they were about to confess or something.

—Even though we were on a date!

Despite insisting it wasn’t a date, those were the words that welled up from her heart. Before she knew it, she was clinging to her stepbrother’s arm, interrupting him.

But when she calmed down and listened, it turned out he just wanted to talk about the accident she’d been in.

—I jumped to conclusions again. So embarrassing…

She couldn’t help but think she’d acted like a child. On top of that, it seemed Himemiya-san already had someone, and her stepbrother even appeared to be cheering them on. In the end, Yuuri was the only one who’d embarrassed herself.

Wriggling on her bed, Yuuri tried to regain her composure and replied to the message.

[It wasn’t a date, but it was really fun. Onii-san’s so kind.]

The best thing about LIME was that no one could see her face—if her best friend saw her now, she’d probably be totally weirded out. Satisfied with sending a perfectly calm and sensible reply, she got an immediate response from Yamanashi.

[Good to hear. I’m relieved.]

The message seemed natural enough, but Yuuri felt a slight sense of unease.

—Maybe it’s just my imagination, but it feels like she’s oddly worried about me…

Come to think of it, when Yamanashi first met her stepbrother, there’d been a subtle awkwardness in the air. Yamanashi probably knew what her relationship with her brother used to be like. Yet, even knowing Yuuri had lost her memories, she never brought it up.

Why was that? Yuuri could tell it wasn’t out of malice—her friend was being considerate in some way.

—Why is she being so careful with me…?

A creeping anxiety spread through her chest. Was her past relationship with her brother something to be worried about?

—No way… Were we not actually close siblings?

The occasional guilt-ridden expressions her stepbrother showed seemed to hint at something like that. But if that were true, it would mean he was lying—after all, he’d said they used to be close.

—But if I was on bad terms with him, and then forgot him entirely, wouldn’t most people not want to get close again…?

They might be kind at first out of family duty, but they wouldn’t act like he did today, going shopping with her like that. Besides, she couldn’t imagine her stepbrother doing something so sneaky.

So she didn’t want to doubt him, but the strange unease kept bubbling up. Now that she thought about it, it was odd that her family never touched on anything from before, despite the bizarre event of her forgetting her brother. She understood they were being considerate, but was that really the only reason?

—Dad and Mom haven’t changed their attitudes or anything.

Still, something felt off, like it didn’t quite fit. Or maybe she was just feeling anxious because she couldn’t remember her stepbrother.

[Yuuri, what’s up?]

Lost in thought, she’d let the LIME chat stall. At the puzzled message, she hurriedly tried to reply.

“Ah!”

In her haste, her finger brushed the edge of the screen, scrolling the chat back days at once. Getting back to the original spot would be a hassle now. As she moved to close the app, a particular exchange caught her eye.

[Just talk to your brother properly already.]

[You haven’t had a real conversation in, like, a year, right?]

“Huh…?”

It was a message from Yamanashi, but one she didn’t recognize.

“A whole year without really talking… What does that mean?”

The surrounding messages were filled with stickers, making it hard to grasp the context—she’d sent angry-looking ones, while Yamanashi had responded with exasperated or head-shaking varieties.

She had no memory of this exchange at all.

Checking the date, she saw it was from two weeks ago.

—The day I got into the accident.

In other words, it was a record from just before she lost her memories.

Why hadn’t she thought of this before? She and Yamanashi messaged on LIME every day—they must’ve talked about her stepbrother too.

—Is it because all my memories of Onii-san are completely gone…?

It seemed her memories of discussing her stepbrother with Yamanashi had vanished as well.

But even if they were gone from her mind, the LIME records remained. That meant the truth about her past relationship with her stepbrother was right here.

Still, she hesitated.

[You haven’t had a real conversation in, like, a year, right?]

It was obvious that wasn’t normal. What had happened between her and her stepbrother? If she found out, would they no longer be able to get along like they did today?

—I don’t want that…

But could she keep pretending she hadn’t noticed? That would probably be just as hard.

“What… do I do…?”

The words slipped out unconsciously. Her throat gulped audibly.

The clue to what had happened between them in the past was right in front of her, but something in her head screamed, “You shouldn’t look.”

A shrill, grating sound filled her ears, and she realized it was her own ragged breathing. Before she knew it, her mouth was dry, her throat parched.

She wanted to know. But she was scared. A terror welled up, as if some unimaginable mistake awaited her in those messages.

—But I want to know. I have to know.

Otherwise, she’d be tormented forever by this vague unease and anxiety. In times like this, she felt her stepbrother wouldn’t run away.

“Onii-san, please give me courage…!”

Taking one last small breath to steady herself, Yuuri slid her finger across the screen.

And so, Yuuri learned everything.

◇

“What do I do…? I…”

Her stepsister mumbled, but she didn’t continue. Yuuri’s shoulders trembled slightly, her breathing uneven.

Faced with his stepsister, who looked on the verge of tears, Mahito didn’t know what to say.

“Yuuri, what happened?”

Even when he asked, Yuuri just pressed her face into his chest, not answering. What could’ve happened while he was talking with their father…?

Despite his confusion, Yuuri spoke, as if she couldn’t hold it back any longer.

“I… was a bad kid…”

“Huh?”

The unexpected words only deepened Mahito’s confusion.

—Yuuri, a bad kid? If anything, I’m the one…

That thought made him pause. Hadn’t he just decided to face Yuuri properly? If so, there was an issue he needed to confront first.

Grasping Yuuri’s shoulders and gently pulling her back, he looked directly into her face.

“Yuuri, there’s something I need to tell you too.”

“H-Hyuii?!”

Stumbling, Yuuri’s back hit the wall behind her, letting out a small yelp.

“T-Talk…?”

Tears welled in her eyes as she tilted her head, her silver hair sliding from her shoulder to her chest.

Taking a moment to steady his breath, Mahito spoke. “You and I… we weren’t actually that close.”

Yuuri’s eyes widened. “Wha…?”

“I don’t think we were fighting, and we didn’t yell at each other or anything. But we… well, we barely talked.” Back then, all Mahito could do was turn his back and avoid her. “That day, the day of your accident, you were trying to say something to me, but I didn’t listen properly.”

It might’ve been something trivial. She was making tea, so maybe she was just asking if he wanted some. But he’d never know the answer now.

He still regretted it. If he hadn’t brushed it off thinking he could hear it tomorrow, if he’d just listened…

—I can’t repeat that mistake again.

This time, he had to be brave. “So if we’re talking about who’s bad, I’m the one at fault.”

“That’s not…”

His words might be selfish, self-indulgent even. But Yuuri shook her head at his confession of guilt.

Mahito looked straight into his stepsister’s eyes again. “That’s why I want to talk to you properly, Yuuri. I want to know you.”

He could never confirm what she’d tried to say that day. But he could still learn about the Yuuri of now. He wanted to talk, to understand what she was thinking, what she felt. And he wanted her to know him too.

Wasn’t that what facing each other meant?

—If I don’t start there, I won’t know what kind of siblings I want us to be.

Yuuri listened to his confession without looking away, taking it all in. Then, she gently touched the hands still holding her shoulders. “Onii-san, thank you…” She smiled, as if relieved. “I was a bit shocked, but you’ve always been kind to me. So I don’t think you’re bad.”

“Yuuri…”

As they stood there, Mahito noticed Yuuri’s face gradually turning red.

“Yuuri?”

“U-U-Uh, um, Onii-san, you’re, like, really close…!”

Her words made him realize the situation. He was gripping his delicate stepsister’s shoulders, pressing her against the wall. It looked, well, like he was cornering her.

“A-Ah, no, this isn’t what it looks like!”

“I-I know, I get it!”

Then, he felt a gaze and turned around. They were making a commotion in the hallway. Their father peeked out from the study with a worried look. Glancing the other way, he saw their mother peeking from the stairwell, her expression brimming with curiosity—or rather, nosy gossip.

“…No, I didn’t see anything.” Their father suddenly acted like his glasses had fogged up, wiping them with a handkerchief as he retreated into the study.

“Oh my, you two, don’t disturb the neighbors, okay?” Their mother, as if suddenly remembering an errand, scurried down the stairs.

““It’s not like that!””

Mahito chased after their father, and Yuuri after their mother, spending the whole night clearing up the misunderstanding.

Because of that, he missed his chance. The real reason Yuuri had looked like she was about to cry.

◇

[If something like a god really exists, they must have a terribly cruel personality.]

Scrolling through LIME to understand the messages, Yuuri found that one waiting. The sender was herself.

Looking further, it continued.

[I wouldn’t have met Onii-chan if we weren’t siblings, but as siblings, we can’t fall in love.]

With that single line, Yuuri understood everything.

—Oh… So that’s what it was…

Back then, Mahito must have been her real, blood-related brother in her mind. Knowing they were siblings, she’d fallen in love with him.

It sounded absurd.

But there were clues.

First, there was how Yamanashi acted oddly around her stepbrother. If she knew how Yuuri used to feel, it’d be natural to struggle with how to react. Yuuri felt truly sorry for putting her in that position, but she was endlessly grateful to her friend for playing along quietly.

Yamanashi’s messages were a response to Yuuri’s feelings.

[Just talk to your brother properly already.]

[You haven’t had a real conversation in, like, a year, right?]

To Yamanashi’s perfectly reasonable point, Yuuri had replied,

[No way. When I’m face-to-face with Onii-chan, my chest tightens, and I can’t get the words out.]

She could understand that feeling a little now. He was unconditionally kind just because she was his sister, always looking at her so directly.

—Yuuri, I love your hair. It’s beautiful.

Those words had helped her accept herself. Without them, she might’ve grown up seeing not just her hair but herself as something pitiful.

Those words must have come from her stepbrother.

—But Onii-san and I are siblings…

It was a forbidden feeling. Or it was supposed to be.

Yuuri’s messages continued.

[If I could forget these feelings, would it make things easier… Or If Onii-chan and I weren’t bound by blood, would I have been spared this pain…]

She was stunned. This situation was something she’d wished for.

—I have to apologize to Onii-san…

Because she’d thought such things, she’d really forgotten him. What a terrible person she was. She’d hurt her kind stepbrother with her selfish feelings.

Stumbling out of her room, she didn’t know how to apologize for something like this.

“—Yuuri, what happened?”

Lost in a daze, she heard her stepbrother’s surprised voice.

“—That’s why I want to talk to you properly, Yuuri. I want to know you.”

As he desperately tried to comfort her, Yuuri finally realized.

—That’s right. Whether we’re siblings or not doesn’t matter.

Even after losing her memories, she’d ended up feeling the same way.

If there was such a thing as a god, it was either terribly cruel or stubbornly inflexible.

But a girl in love was just as inflexible.

And so, Yuuri made a certain resolve.